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What distance should my light be from my plants?

Antics

420 Member
When speaking in CFL wattage, just discuss the actual wattage. Equivalent wattage is just so people can replaace an incandescent bulb with a CFL of similar brightness. Since Incandescent bulbs can't grow plants, that number is useless for our purposes.

So I'm guessing about 45 watt bulbs? You should be fine 1"-3" away for seedlings, and I'd turn off the LED for now. There's a risk the LED lighting could be too intense, and can damage seedlings.
 

betsylee11

Spambot
Yeah. you are correct.

Spectrum of Light : Vegetated Stage - 430-475nm, 620-630nm, 660nm and White

Spectrum of Light: Growth & Bloom - 430-475nm, 620-630nm, 660nm, 730nm and White
 

Caper92

New Member
Hey everyone. I'm brand new to growing. I stumbled upon this site and there is a lot of really good info on here. I have a question. I am growing indoors with a 180 watt full spectrum LED. I have no idea how high to set the light. I have it around 2 feet now. The plants seem to be doing fine. But this is my first grow and I could use some advice. I'm growing in soil and I have only watered them, nothing else. They are a month old now. Any suggestions are welcome.
 

drcannabi

New Member
Hey everyone. I'm brand new to growing. I stumbled upon this site and there is a lot of really good info on here. I have a question. I am growing indoors with a 180 watt full spectrum LED. I have no idea how high to set the light. I have it around 2 feet now. The plants seem to be doing fine. But this is my first grow and I could use some advice. I'm growing in soil and I have only watered them, nothing else. They are a month old now. Any suggestions are welcome.
Hi Caper!

I've been using California Light Works and they recommend 18 - 24 inches. I just bought a BudMaster-II 675 GOD and they recommend hanging it at the very top of the tent (6.5 - 7.5 feet).

It really depends on the light itself. The composition of the parts (build quality), as well as design determine the correct distance from the top of the canopy as well as the optimum footprint. The more distance you have, the larger the footprint will be, but you'll lose yield if you hang your light too high. The key is to experiment until you get it just right. It may take a couple grows.

If your light is a true 180 watts (most use only 1/2 to 3/4 of the available power for a multitude of reasons), 18 - 24 inches would "probably" be a great place to start. If it's less (which I suspect), you could "probably" lower it 4 - 6 inches.

If you don't have (or can't get) the manufacturer's recommendation (which is still just a recommendation) I would hang that light 18-24 inches from the top. Be sure to keep an eye on bleaching, that's a sign your way too close. Bleaching turns the effected area white and those buds generally aren't very good quality. The only time it ever happened to me was when I had the main cola 8 inches from the light.

I've personally used 3 different types of LEDs and they all had a different sweet spot. Even different models from the same manufacturer have different height recommendations.

Hope this helps you out buddy!
 

maryjhomegrow

New Member
I am simultaneously using 2 CFL bulbs:

1. 325W
2. 150W



So, that adds to 475W altogether for 2 early veg stage plants in one small grow room

They are both 6500K Colour Temperature

What distance should my bulbs be from the plants? They are currently about 2-4 inches away, I can put my hand very close to the bulb and it isn't uncomfortable
 

FlowerChild74

New Member
I am vegging in a closet, using HygroFarm 125Wt. CFL Tube bulb. I have 5 seedlings under it that have three sets of leaves so far. They are about 7-8 inches away and are doing well. I just would like to know when I should move the light further away from the plants. One of the seedlings seems to have some curling leaves. Could this be a sign to move them further away from the light now? If so, what distance should they be for optimal results? Thanks in advance for any advice anyone can give me on this subject.
 

OregonMist

New Member
I run mine in the 18"-24" range for years and it's worked fine. Your plants will let you know if you're too close or too far away. Happy growing!
 

SilentMurder

New Member
Im using a 1000 watt Mh light, 20 inches from 13 day old plants. My light meter says 100k -110k lumens. Temp 80-88 degrees. Plants seem to be fine so far but im worried i am overdoing it. Are my temps or lumens to high? My cooling duct fan is on the way, hopefully soon! TY, im new to growing!
 
That's a little close to your plants for being 13 days old. Bring your light up about another foot or so. That will bring your temps down as well. That's a bit too hot for little seedlings. Make sure you have a fan or 2 to make sure you have good ventilation. This is my first grow as well.
 
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